Download Endocrine System Notes - Wiki-Health

A lot! Your body produces its own
chemicals and uses them to control
certain functions, and the main system
that coordinates these chemicals is
called the endocrine system.
A quick overview
http://www.youtube.com/watch?v=rS7SM4vzs18
http://www.youtube.com/watch?v=Vae5CcaPN_8
http://www.youtube.com/watch?v=qzjjW--I-2Q&feature=related
Though we rarely think about the endocrine
system, it influences almost every cell, organ,
and function of our bodies.
It regulates mood, growth and development,
tissue function, metabolism, sexual function
and reproductive processes.
The endocrine system is in charge of body
processes that happen slowly, such as cell
growth
Faster processes like breathing and body
movement are monitored by the nervous
system. But even though the nervous
system and endocrine system are
separate systems, they often work
together to help the body function
properly.
Endocrine System - Is a chemical system that regulates many body
functions through a network of glands throughout the body
Glands- A group of cells that secrete chemicals
Glands select and remove materials from the
blood, processes them, and secretes the finished
chemical product for use somewhere in the body
The glands of the Endocrine System are (13 of them)
Hypothalamus
Thyroid
Adrenal Glands
Reproductive Glands
Thymus
Kidney
Intestines
Pituitary
Parathyroid
Pineal body
The Pancreas
Heart
Stomach
Hormones
• Chemicals that circulate the blood stream
and carry messages and signals to different
parts of the body
• The word hormone comes from the Greek
word hormao which means “I excite”
meaning that hormones stimulate particular
parts of the body (Target Glands)
Located in the lower central part of the brain
Main link between the endocrine and
nervous system
Control the pituitary gland by
producing chemicals that either
stimulate or suppress hormone
secretions from the pituitary.
Hypothalamus
• Most doctors feel the hypothalamus is to blame for
mind problems since it controls the bodies most
important hormones
• Serotonin, Dopamine, Norepinephrine,
Acetylcholine among others
• The main function of the hypothalamus is to
maintain homeostasis… blood pressure,
temperature, fluid and electrolyte balance
• The hypothalamus controls the Pituitary Gland
Located right beneath the hypothalamus
About the size of a pea but considered to be the most important
part in the endocrine system
Known as the “master gland” because it makes hormones that
control several other endocrine glands (Makes 8 types of hormones)
Production and secretion of pituitary hormones can be influenced
by emotions and change of seasons
To do this the hypothalamus sends information sensed by the brain
(Temperature, light exposure, feelings) to the pituitary
The gland is separated into two sections
Anterior Lobe
Posterior Lobe
Pituitary also secretes
Endorphins which aid in
Pain relief
Anterior lobe regulates the activity of the thyroid, adrenals, a
reproductive glands, bone growth, and skin (It secretes 6
different hormones)
It produces:
Growth hormone (GH) – One of the most important hormones, stimulates all
the tissues in the body to grow this includes bones (Effects protein
formation)
Luteinizing Hormone (LH) – Stimulates sex glands in both sexes to either
produce ripe eggs or mature sperm
Thyrotrophin (TSH) - which stimulates the thyroid gland to produce thyroid
hormones. Responsible for overall metabolism of the body
ACTH or Corticotrophin – Effects the stereroid hormones (Adrenal) that control
Stress response
Also controls melanocytes – causing more melanin to be produced
Releases Antidiuretic Hormones (ADH)
helps control the balance of water in the body. Permits more water
To be stored by the body (Kidneys are affected)
Oxytocin – aids in the release of milk from mammary glands as
well as controls uterine contractions during child birth
The pituitary gland also controls ovulation
and menstrual cycle in women as well as
secreting hormones to the reproductive system
To make sex hormones
(Gonadotrophins)
The thyroid has the
Only cells of the body
That can absorb iodine
Located in the front part of the lower
neck, is shaped like a bow tie or butterfly
Produces the thyroid hormones thyroxin (T4) and
triiodothyronine try-eye-uh-doe-thy-ruh-neen(T3)
Number has to do with amount of iodine molecules
These hormones control the rate at which cells
burn fuels from food to produce energy
The more thyroid hormone in a persons body
the faster chemical reactions occur in the body
Thyroid hormones also play a role in bone growth and brain / nervous
system in young children. Affects Mood and Memory!
Thyroid hormones build
strong bones and develop
the brain and nervous
system
People with hypothyroidism
Do not produce enough thyroid hormone
To maintain proper metabolic functioning
Attached to the thyroid the parathyroid are 4 tiny glands which
regulate the amount of calcium in your blood. This
Gland acts on the bones of your body.
Though the parathyroids are attached and sometimes found
Inside the thyroid but have no relation
This system is important because calcium allows
Normal conduction of electrical currents along
Nerves… it is how our nervous system works!
Calcitonin
Parathyroid
• Calcium production is also important…
• The brain works on fluxes of calcium into
and out of the nerve cells
• Calcium is the primary element which
causes our muscles to contract
Quiz
• What is the main purpose of the endocrine
system?
• What is the proper name for the master
switch? Why is it called the master switch?
• Name the two hormones that the posterior
lobe secretes.
• What hormones are secreted by the thyroid
gland, what does it control?
Two triangular glands found on top of each kidney
There are two sections to each gland
Adrenal cortex - The outer part that regulates salt and water
balance in the body… also plays minimal roles in the bodies use of fats /
Proteins as well as inflammatory reactions of the immune system
Adrenal medulla - The inner part that increase blood pressure
and heart rate when stress level rises (Norepinephrine / Epinephrine)
AKA Adrenaline or catecholamines (kat-tuh-ko-luh-meenz)
Located in the middle of the brain
Secretes melatonin a hormone that helps you regulate
when you sleep at night or when you wake up in the morning
Both Girls and Guys have gonads; Testes in males Ovaries in females
Produce androgens a male sex hormone also testosterone (Males)
Produce estrogen and progesterone (Females)
Control development of sex characteristics in both males and
females
Although the endocrine glands are the body's main
hormone producers, some other organs not in the
endocrine system - such as the brain, heart, lungs,
kidneys, liver, and skin - also produce and release
hormones
Pancreases - Produces insulin and glucagon which work
together to maintain the proper sugar level in the blood
And supply the body with energy
Islets of Langerhans - cell clusters responsible for controlling
glucose production
I am glad you asked
Once a hormone is secreted it travels through the blood
stream to the designated cells
These are called TARGET CELLS
On the way to the target cells certain proteins
join on to the hormones to control how much
of the hormone is used by the target cells
Each hormone has it’s own designated receptor site (Target Cell)
once it locks in, the combination gives chemical instructions
to the inner workings of the cell
When hormone levels reach a certain normal
amount, the endocrine system helps the body
to keep that level of hormone in the blood
For Example lets say that your body was in a situation where
It needed to produce more sex hormone
The Hypothalamus receives information from monitoring cells
The hypothalamus then produces gonadotrophin to the pituitary
The pituitary releases gonadotrophin
This LH finds it’s ways to the testes and levels begin to rise
The turning off process or regulation of hormone is called
a negative feedback system
Endocrine System
To much or to little of any hormone can be bad for your body
For example, if the pituitary gland produces too
much growth hormone, a teen may grow
excessively tall. If it produces too little, a teen may
be unusually short
Doctors can usually control the endocrine system by regulating
the production of hormones or by using medications